Paint gun



.5. D. MURRAY Sept 2 B 1924.,

PAINT GUN Filed Nov. 10,, 1922 Inva id-59 01 :7 I [larney N, 3 3 w firwm g wwmmwr Patented Sept. 2,

entree PAINT GUN.

Application filed November 10, 1922. Serial No. 599 994.

To all whom it may concern:

Be it known that 1, JOHN D. MURRAY, a citizen of the United States,residing in the city and county of San Francisco and State ofCalifornia, have invented certain new and useful Improvements in PaintGuns, of which the following is a specification.

The present invention relates to that type of devices employed forspraying or applying liquids by air under pressure, and which devicesare known to the trade under the common names of air brushes or paintguns.

The invention consists broadly in a handpiece into which are ledconduits or channels through which are supplied fluids under pressure,one preferably being in the form of a liquid, and within which thefluids are intermixed in controlled proportions and are discharged as anatomized product.

Among the objects of this invention is the provision of a novel type ofdischarge tip enablin the application of a flat stream of thoroug ly anduniformly mixed material of any desired width or volume to a surface atlow pressure, enabling the position ing of the nozzle in close proximityto the work, thus eliminating splashing or spray Waste and affording amaterial saving in material and insuring the impregnating of the surfaceto be coated with the material.

Another object is the provision of a novel form of control, whereby thematerial and conveying and atomizing agent maybe independently varied toadmit of the correct respective proportions of each as may be desired toenter the mixing chamber to be thoroughly intermixed therein prior todischarging in spray form from the nozzle tip.

A further object is to provide a construction which is light in weight,compact and easy to clean, and which is equipped with but few controls,capable of being readily adjusted by the operator on the job without thenecessity of the operator returning to the source of material supply foradjusting its flow therefrom.

W'ith the above mentioned and other ob jects in view, the inventionconsists in the novel construction and combination of parts hereinafterdescribed, illustrated in the accompanying drawings, and set forth inthe claims hereto appended, it being understood that various changes inthe form, proportion, size and minor details of construction within thescope of the claims may be resorted to without departing from the spiritor sacrificing any of the advantages of the invention.

To more fully comprehend the invention reference is directed to theaccompanying drawings, wherein z- Figure 1 is a view in side elevationpartly in section of the preferred embodiment of my invention.

Figure 2 is a view in end.elevation of the apparatus illustrated inFigure 1.

Figure 3 is a sectional view taken through the controlling valve on line33 of Figure 1 viewed in the direction of the arrow.

Figure 4 is a transverse section on line 4--t of Figure 1 viewed in thedirection of the arrows.

Figure 5 is a view in detail section of the united valves forsimultaneously controlling the inlet channels, the view being taken online 55 of Figure 1, viewed in the direction of the arrows.

Figure 6 is a fragmentary detail sectional view taken on line 66 oi?Figure 3, and

Figure 7 is a similar view taken on line 7-7 of Figure 3. E

Figure 8 is a longitudinal sectional view of the tip removed from thenozzle.

gigure 9 is a view in plan of the tip core, an

Figure 10 is a similar view of the domed discharge tip illustrating thetransverse discharge slot therein.

Referring more particularly to the several views of the drawings whereinlike characters of reference designate corresponding parts, 1 indicatesa hand-piece preferably formed with a solid head 2, and separable stockplates 3, united together by screws or other fastening means 4 to form ahand grip. Within registering grooves 5 disposed longitudinally betweenthe meeting faces of the pieces 3 are received the tubes or pipes 6 and7, the pipe 6 being adapted for conducting air under pressure and thepipe 7 being adapted for conducting a liquid under pressure.

In the present embodiment, the liquid referred to is preferably paint.The head 2 is formed interiorly with the parallel inlet channels 8 and9, which are connected by a transverse channel hereinafter termed anoutlet channel 10, which extends interiorly through the end of the head2. The channel 8 preferably connects with the air inlet pipe {5 and thechannel 9 connects with the li uid inlet pipe 7, the channel 8discharging into the outlet channel 10 through a port 11 and the channel9 discharging into the outlet channel 10 through a port 12. The outerend of outlet channel 10 provides a main mixin chamber for the fluidsadmitted throug pipes 6 and 7. The passage of the fluids through thepipes 6 and 7 into the channels 8 and 9 is controlled .by a valvestructure mounted within a transveYse recess '13 formed in the head 2between the, ends. of

the valve members 14, which are of a di-.

ameter-to snugly fit the interior diameter of the bore 13. The members14 are connected in spaced relation by a stem 15, and are so spaced sothat one will overlie the end of the respective pipes 6 and 7 as inFigure 5; An operating handle 16, connected to the valves by the reducedstem 17, ispositioned exteriorly of the handpiece 1 to be readilygripped by the fingers of the operator and forced inwardly when theoperator grasps the-hand-piece. A spring 18, retained under tensionwithin a-cup 19 and bearing against the end of the inner valve 14normally maintains said valves in a position to close'the discharge endsof said pipes 6 and 7 andin contact with a retaining pin 20/ passingtransversely across the'bore 13. It will be observed that the inwardmovement of this pair of valves 14 causes a corresponding opening of thedischarge ends of the pipes 6 and 7 to admit of the passage therefrom ofmaterial conveyed into the channels 8 and 9. The volume of materialadmitted into the channel 9, which, as previously explained, ispreferably paint, is adapted to be further controlled by an auxiliaryvalve 21 which extends into the channel 9, and which at its point ofintersecting the channel is provided with transverse cutout ordepression 22. The valve is threaded within an opening 23 in thesidewall of the head v2, and a packing gland 24 prevents the escape ofpaint around the same. A slight rotation of the valve 21 varies the areaof the channel 9 at its point of passage therethrough and controls thepaint or liquid adapted to be forced through said cutout or depression22.

Over the discharge end of the outlet 10 is removably positioned asuitable atomizing or spray tip, and the same consists of an annularshell 25 adapted for reception within the discharge end of the outletchannel 10, and said shell 25 is provided with a dome discharge tip end26, transversely slotted as at 27 and provided with the exteriorshoulder 28 and the interior shoulder 29, illustrated in Figure 8.Removably fitted within the dome discharge tip 25 and adapted forreception within the discharge end of the outlet channel 19 is acylindrical core 30, provided with an annular shoulder to receive theshoulder 29 of the tip 25, and said core is provided with the conicaldischarge port 31 terminating at its apex in the contracted outlet32'which. dischar es into the transverse slot 33 formed rounded projection34 of the core which is received withir'ithe' inner ,.recess 35 ofthedome 26. The recess'35 is adapted to lafe ford a final mixing chamberforthe ma? terial to be sprayed, and the transverse slot 27 insures thedischarging of the material from the tip in a flat-stream of the desiredvolume' and width depending upon the ad- ,justment of the controllingyalves.

A needle valve 36 is mounted in the outlet channel 10 and the needle end37 thereof is adapted to coact with the tapered wall of port 31 andcontrol the mixed fluid volume adapted to passthrough said tip.

longitudinally of the needle valve to intermix with the paint whichpasses upwardly through the channel 12 into the annular groove 39 in theneedle valve.

The limited air pressure admitted through groove 40 causes a withdrawalof the paint from the channel 12 and forces the same through the grooves41.

It will be understood its adjustment controls the size and character ofspray discharged from the domed discharge tip 26.

By my present construction, I have found it necessary and essential inobtaining a flat flaring discharge stream from the nozzle tip toprovide-a chamber 35 between the tip and core, as if this chamberis notprovided, the desired result is not obtained.

Having thus described my invention what I claim as new and desire toprotect by Letters Patent of the United States is 1. A liquid applyingapparatus including a hand-piece provided with independent channels, amixing chamber in the hand piece into which said channels discharge abulbous discharge tip at the discharge end of said mixing chamber andformed with a single discharge slot extending entirely across the same,and means for controlling the passage of fluid through said channels.

2. A liquid applying apparatus including-1 that the valve 36 in ahand-piece provided with independent channels, a mixing chamber in thehand piece into which said channels discharge, a discharge tip at thedischarge end of said mixing chamber having a spheroidal end, said tipprovided on its interior with a hollow domed chamber, the spheroidalwall of said chamber being formed with a single transverse slotproviding a discharge opening, and means for controlling the passage offluid through said channels.

.3. A liquid applying apparatus including a hand-piece provided withindependent channels, a mixing chamber in the hand piece into which saidchannels discharge, a hollow bulbous tip over the discharge end of saidchamber, said tip provided in its wall with a single transversedischarge slot extending entirely across the same, a core removablypositioned within said the inner surface of the wall of said bulbous tipwith its wall in spaced relation to said tip, said core provided with asingle outlet port, and means for controlling the passage of fluidthrough said channels.

4:. A liquid applying apparatus including a hand-piece provided with apair of independent inlet channels and an outlet channel into which saidinlet channels discharge, said outlet channel provided with a dischargeorifice, a slotted discharge tip over said discharge orifice, a needlevalve within said outlet channel for controlling the discharge ofmaterial through said tip, a valve within one of said inlet channels forcontrolling the maximum fluid passage therethrough, and a pair ofconnected valves one within each inlet channel and adapted forsimultaneous operation on the gripping of the hand-piece.

5. A liquid applying apparatus includmg a hand-piece provided with apair of independent inlet channels and an outlet channel into which saidinlet channels discharge,

' said outlet channel being provided with a conical discharge orifice, aneedle valve within said outlet channel and disposed with its outer endadapted for reception within said conical discharge orifice, said valveprovided with a pair of annular depressions one for movement intoregister with the discharge end of each of said inlet channels,.saidvalve provided with a groove connecting said depressions, and with asecond groove connecting one of said depressions with the needle end ofsaid valve.

6. A. liquid applying apparatus including a hand-piece provided withindependent inlet channels and an outlet channel at substantially rightangles thereto and into which the same discharge, said outlet channelprovided with a discharge'port at one end, a discharge tip associatedwith said ported end and provided with a discharge orifice, and a needlevalve within said outlet channel adapted for adjustment to control thepassage of material through said discharge orifice, the body of saidvalve at a point inwardly from said needle point being cut to provide apair of conical depressions disposed with their apices toward each otherin spaced relation, said valve body between said conical depressions andbetween the outer of said depressions and said needle point beinglongitudinally grooved.

7. A liquid applying apparatus including a hand-piece provided withindependent inlet channels and an outlet channel at substantially rightangles thereto and into which the same discharge, said outlet channelprovided with a discharge port at one end, a discharge tip associatedwith said ported end and provided with a discharge orifice, a needlevalve within said outlet channel adapted for adjustment to control thepassage of material through said discharge orifice, the body of saidvalve at a point inwardly from said needle point being cut to provide apair of conical depressions disposed with their apices toward each otherin spaced relation, said valve body between said conical depressions andbetween the outer of said depressions and said needle point beinglongitudinally grooved, and a pair of connected valves one within eachinlet channel and adapted for simultaneous operation on the gripping ofthe hand-piece to control the passage of fluid through said channels.

8 A liquid applying apparatus including a hand-piece provided with apair of independent channels and an outlet channel into which the samedischarge, said outlet channel being provided with a discharge orifice,

valve mechanism provided with a needle end and positioned within saidoutlet channel for controlling the discharge through said orifice, adischarge tipassociated wlth said orifice and includin a hollow bodyprovided with a domed en and formed with a transverse discharge slot,and a cored member removably fitted within said body with its outersurface in spaced relation to the domed end of said tip, said coreprovided with a tapered orifice in'line with said discharge slot andwithin which said needle end is adapted to co-operate.

in testimony whereof it have signed my name to this specification.

JOHN D. MURRAY.

